When UHF satcom antennas are vehicle mounted, they typically need to be elevated for better reception capability, thus necessitating a riser so that the vehicle itself no longer provides a ground plane for the antenna. Hence, when the antenna is not directly mounted to the vehicle, an alternative ground plane is needed. It is known to provide a metal disc on the riser to serve as a ground plane. But typical disc-style ground planes can be damaged by impacts in the field. Damage to the ground plane negatively affects performance of the UHF satcom antenna.